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authorJosef Bacik <josef@redhat.com>2009-11-11 15:53:34 -0500
committerChris Mason <chris.mason@oracle.com>2009-11-11 15:53:34 -0500
commita6dbd429d8dd3382bbd9594b8d2ec74843a260d9 (patch)
tree9cc6426da748996e4e1cc61d446052838703434f
parent33b258086441dd07e00133c79fcd8cbc6a76d737 (diff)
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Btrfs: fix panic when trying to destroy a newly allocated
There is a problem where iget5_locked will look for an inode, not find it, and then subsequently try to allocate it. Another CPU will have raced in and allocated the inode instead, so when iget5_locked gets the inode spin lock again and does a search, it finds the new inode. So it goes ahead and calls destroy_inode on the inode it just allocated. The problem is we don't set BTRFS_I(inode)->root until the new inode is completely initialized. This patch makes us set root to NULL when alloc'ing a new inode, so when we get to btrfs_destroy_inode and we see that root is NULL we can just free up the memory and continue on. This fixes the panic http://www.kerneloops.org/submitresult.php?number=812690 Thanks, Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
-rw-r--r--fs/btrfs/inode.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index d3d7d46a6af2..ee92801fc5db 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -5180,6 +5180,7 @@ struct inode *btrfs_alloc_inode(struct super_block *sb)
ei->logged_trans = 0;
ei->outstanding_extents = 0;
ei->reserved_extents = 0;
+ ei->root = NULL;
spin_lock_init(&ei->accounting_lock);
btrfs_ordered_inode_tree_init(&ei->ordered_tree);
INIT_LIST_HEAD(&ei->i_orphan);
@@ -5196,6 +5197,14 @@ void btrfs_destroy_inode(struct inode *inode)
WARN_ON(inode->i_data.nrpages);
/*
+ * This can happen where we create an inode, but somebody else also
+ * created the same inode and we need to destroy the one we already
+ * created.
+ */
+ if (!root)
+ goto free;
+
+ /*
* Make sure we're properly removed from the ordered operation
* lists.
*/
@@ -5230,6 +5239,7 @@ void btrfs_destroy_inode(struct inode *inode)
}
inode_tree_del(inode);
btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
+free:
kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
}